U.S. Geological Survey Home AASG Logo USGS HOME CONTACT USGS SEARCH USGS
National Geologic Map Database
Geologic Unit: Shuksan
Search archives
Map showing publication footprint
  • Usage in publication:
    • Shuksan formation
  • Modifications:
    • Named
  • AAPG geologic province:
    • Cascades province
Publication:

Weaver, C.E., 1945, Geology of Oregon and Washington and its relation to occurrence of oil and gas: American Association of Petroleum Geologists Bulletin, v. 29, no. 10, p. 1377-1415. [Available online, with subscription, from AAPG archives: http://www.aapg.org/datasystems or http://search.datapages.com]


Summary:

Named spelled "Shukson" in table of rocks in northern Cascades, WA. Described as marine sediments, partly metamorphosed and of Late Jurassic age.

Source: GNU records (USGS DDS-6; Menlo GNULEX).


Map showing publication footprint
  • Usage in publication:
    • Shuksan greenschist
  • Modifications:
    • Redescribed
  • Dominant lithology:
    • Schist
  • AAPG geologic province:
    • Cascades province
Publication:

Stout, M.L., 1964, Geology of a part of the south-central Cascade Mountains, Washington: Geological Society of America Bulletin, v. 75, no. 4, p. 317-334.


Summary:

In discussion of Easton Schist of Smith (1903) author cites Misch's (1952, 1959, 1960) references to the Shuksan belt and to its rocks as the Goat Mountain phyllite and the Shuksan greenschist. Name Easton Formation or Group would be more appropriate since Easton Schist has chronologic priority. "In this case the Shuksan greenschist would include the thick section of greenschists with intercalated blueschists." p.323

Source: GNU records (USGS DDS-6; Menlo GNULEX).


Map showing publication footprint
  • Usage in publication:
    • Shuksan Greenschist
  • Modifications:
    • Revised
  • AAPG geologic province:
    • Cascades province
Publication:

Misch, Peter, 1966, Tectonic evolution of the Northern Cascades of Washington State, IN Symposium on the tectonic history and mineral deposits of the western Cordillera: Canadian Institute of Mining and Metallurgy Special Publication, v. 8, p. 101-148.


Summary:

Shuksan Metamorphic Suite underlies structural belt on west side of metamorphic core of Northern Cascades. Diagrammatic map of Shuksan thrust plate shows Straight Creek fault on east side. Shuksan Suite on western flank of range comprises Darrington Phyllite and overlying metabasaltic Shuksan Greenschist that consists of actinolite greenschist with blueschist intercalations. Depositional age of Shuksan Suite is not known but is presumed Paleozoic and may be pre-Middle Devonian.

Source: GNU records (USGS DDS-6; Menlo GNULEX).


Map showing publication footprint
  • Usage in publication:
    • Shuksan Greenschist
  • Modifications:
    • Age modified
  • AAPG geologic province:
    • Cascades province
Publication:

Brown, E.H., Blackwell, D.L., Christenson, B.W., Frasse, F.I., Haugerud, R.A., Jones, J.T., Leiggi, P.A., Morrison, M.L., Rady, P.M., Reller, G.J., Sevigny, J.H., Silverberg, D.S., Smith, M.T., Sondergaard, J.N., and Ziegler, C.B., 1987, Geologic map of the northwest Cascades, Washington: Geological Society of America Map and Chart Series, MC-61, 1 sheet, 10 p., scale 1:100,000


Summary:

Shown on cross sections and geologic map of northwest Cascades, WA. Is interpreted to have underlain Darrington Phyllite prior to orogeny. At Gee Point is in fault contact with Deer Peak Metavolcanics of Paleozoic age. At Diobsud Creek and Sauk River overlies rocks of Chilliwack Group of Paleozoic age. Metamorphic age of Shuksan Greenschist is shown as Cretaceous. Protolith age is indicated as Jurassic.

Source: GNU records (USGS DDS-6; Menlo GNULEX).


Map showing publication footprint
  • Usage in publication:
    • Shuksan Greenschist*
  • Modifications:
    • Adopted
  • AAPG geologic province:
    • Cascades province
Publication:

Tabor, R.W., Frizzell, V.A., Jr., Booth, D.B., Waitt, R.B., Whetten, J.T., and Zartman, R.E., 1993, Geologic map of the Skykomish River 30' x 60' quadrangle, Washington: U.S. Geological Survey Miscellaneous Investigations Series Map, I-1963, 1 sheet, 42 p., scale 1:100,000 [http://ngmdb.usgs.gov/Prodesc/proddesc_10042.htm]


Summary:

zzzzzShuksan Greenschist of Easton Metamorphic Suite. Easton terrane. Metamorphosed about 130 Ma (Early Cretaceous), based on K-Ar and Rb-Sr isotopic dating (Brown and others, 1982, p. 1096). Protolith age about 164 Ma (late Middle Jurassic), based on Pb-Pb zircon age from metadiorite pluton that appears to be part of protolith igneous suite of Shuksan (Brown, 1986, p. 146).

Shuksan Greenschist as defined by Misch (1966) is adopted (as part of the herein-revised Easton Metamorphic Suite). Metamorphic age is given as Early Cretaceous. [Type locality on Mount Shuksan, Northern Cascades, north-central WA.]

Source: GNU records (USGS DDS-6; Menlo GNULEX).


Search archives

For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.

Asterisk (*) indicates published by U.S. Geological Survey authors.

"No current usage" (†) implies that a name has been abandoned or has fallen into disuse. Former usage and, if known, replacement name given in parentheses ( ).

Slash (/) indicates name conflicts with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). May be explained within brackets ([ ]).

Accessibility FOIA Privacy Policies and Notices

USA Gov U.S. Department of the Interior | U.S. Geological Survey
Supported by the National Cooperative Geologic Mapping Program
Page Contact Information: Personnel
Page Last Modified: Thu 04 Apr 2024 04:17:11 PM MDT